(3-Carboxy-5-oxo-5H[1]benzopyrano[2, 3-b]pyridin-2-yl)acetic acid derivatives (3 and 4) were found to possess potent antiarthritic activity in the rat adjuvant arthritis model. The mode of action of these compounds differs from that of acidic antiinflammatory drugs. Various modifications in these compounds (e.g., elongation, removal, or substitution of the methylene group of the acetic acid moiety; and substitution of the benzene ring) were made in order to study the structure-activity relationships. However, it was found that the structural requirements for the compounds to show activity are rather severe.